Can one optical fibre transmit multiple networks Can a single optic fibre installation transmit multiple connections, For example, There are two networks, each network sends and receives data to or from. My question is can both the two networks be transmitted through a wired optic fibre? Please correct me if am wrong

I think you don't really understand what you are asking. A fiber is a layer-1 link and it will transmit network traffic. It doesn't matter the what the source or destination addresses are on the layer-3 packets; the fiber neither knows or cares what network traffic it carries.

What matters is that you use routers. Routers route traffic between networks. You terminate the fiber with a router on each end, and use a routing protocol between the routers to share routes between the routers.